It was one of the most poignant images of a Polish national tragedy: a kneeling Jaroslaw Kaczynski whispering to his identical twin's flag-draped coffin after the president's body returned from Russia following a plane crash.

The image of grief triggered a flood of sympathy for the former prime minister who had risen to the pinnacle of Polish power hand-in-hand with his brother, Lech. Now questions have started about whether anguish is affecting the surviving twin's judgment.

National mourning ensured that Kaczynski would come close to winning the presidency after his brother's death. Defeated, he has shocked the nation with strident diatribes — blaming Moscow for the April crash, suggesting the wrong body was sent back to Poland, accusing political opponents of sabotaging flight safety.

The twins held Poland's attention for decades: they rose to fame as child film stars, advised Lech Walesa as he went from freedom fighter to president, and served simultaneously as president and prime minister. Now the spectacle of a former leader beset by conspiracy theories has again made them the talk of Poland.

"He behaves as if he has not yet come out of the shock after the crash," said Janusz Czapinski, a social psychologist who spoke on a TV news program in late January devoted to analyzing Kaczynski's behavior. "He is still in the second phase of mourning, the phase of revolt, of opposition."

Kaczynski's Law and Justice party filed a formal complaint to state broadcasting regulators, saying the program treated him unfairly. But it's clear Kaczynski is not over his mourning: ten months after the crash, which also killed 95 others, he still only appears in dark suits and black ties and leads regular wreath-laying ceremonies to his brother's tomb, the presidential palace, or other memorial sites that have sprung up.

Even amid the first outpouring of sympathy, Kaczynski stirred controversy when he encouraged the church to inter his brother and sister-in-law in Krakow's Wawel Cathedral, a hallowed place reserved for kings and national heroes. Protesters held rallies in several cities demanding — unsuccessfully — that the president, who had been unpopular, be buried elsewhere.

The first signs of a personality change came when Kaczynski stepped in to run for the presidency.

Gone were his trademark combativeness and suspicion of Russia and Germany. Instead, he appealed for national unity and had warm words for the "Russian friends" who showed Poles kindness after the disaster. Across the country, people asked whether the change was genuine.

His fighting spirit came back with a vengeance after his narrow loss to President Bronislaw Komorowski. He admitted he had been on tranquilizers during the campaign, and ranted about "Russian imperialism" in an open letter to politicians and foreign ambassadors based in Warsaw. Foreign Minister Radek Sikorski asked if Kaczynski was still "on pills" when he sent the letters.

More recently he has suggested that something was amiss with the way his brother's autopsy was handled — saying he identified the body at the crash site in Smolensk, Russia, but when "I saw the body brought to Poland in a coffin, I did not recognize him."

He dismisses outright the accepted explanation for the plane crash — that the Polish crew made a fatal error by trying to land in heavy fog — as an insult to Poland's honor.

Instead he blames Russian air traffic controllers for not ordering the plane to divert to another airport, and the Polish government of Prime Minister Donald Tusk for what he claims was a failure to ensure flight safety for a president it did not like.

"It's their (the Russians') fault that the plane crashed, but the fact that it was possible is the fault of the Polish government," Kaczynski said.

By raising suspicions, he is also giving indirect encouragement to wild conspiracy theories — including one claiming that Russians manufactured fake fog to disorient the pilots.

Those ideas are feeding bitterness and deepening a rift between modern, Western-looking Poles and conservatives who remain deeply suspicious of foreign powers like Russia.

"Jaroslaw Kaczynski has descended into madness because he has said that we are all guilty of the death of 100 people," Tomasz Tomczykiewicz, a lawmaker with the governing Civic Platform party, told reporters on the sidelines of a parliament session last month.

"It is something unbelievable and scandalous to say."

Kaczynski supporters give him the benefit of the doubt.

"He may be wrong accusing the Russians, but before everything is explained, we cannot say for sure," said Monika Dziekan, 42, an unemployed mother. "He is in such a state of emotion that he is entitled to that."

The skepticism toward Russia is strongest among older Poles who still remember World War II, when the Soviet Union invaded Poland's eastern half, and the communist decades, when Moscow controlled the country. Many older Poles of conservative and patriotic bent support Law and Justice, which Kaczynski still heads.

Some see in Kaczynski's accusations a devastated brother lashing out in grief; others suspect a calculated attempt to win votes by stirring up his nationalistic base ahead of elections expected this fall.

Increasingly, however, questions are emerging about the mental state of the 61-year-old.

If Kaczynski's eccentric behavior is part of a strategy it may be working: opinion surveys show Law and Justice maintains support of around 25 percent — enough to make Kaczynski a force in Polish politics, but not to bring him back into government.

With a mix of pro-Catholic and patriotic values, it has a devoted following and is the country's second-most popular party after the governing pro-business party, Civic Platform.

"Law and Justice has usually had success in an atmosphere of high emotions and Kaczynski is cynically using the crash to appeal to that part of the society that is traditionally distrustful of the Russians," said Kazimierz Kik, a political scientist at Kielce University.

Even Kaczynski's most bitter critics do not question his suffering. The brothers were constantly on the phone — even talking by satellite phone minutes before the crash.

"I think of my brother hundreds of times every day," Kaczynski said in a recent interview in the daily newspaper Fakt. "You can say that I do not forget about him even for a moment."

"I've lost a twin brother. Only a person who has had one can understand what that means."