Television ads hit the airwaves as Israel's election campaign headed into the home stretch, but a new scandal threatened to overwhelm the slick advertising and earnest appeals.

The first night of political commercials avoided any mention of twin homicide bombings that killed 22 people in Tel Aviv on Sunday, but themes of security have dominated the campaign leading up to the Jan. 28 vote. The ads are restricted by law to daily blocks of time.

On Tuesday, the Haaretz newspaper reported that Prime Minister Ariel Sharon and one of his sons are the targets of a police investigation over a $1.5 million deposit made by a South African millionaire.

Citing a document obtained from Israel's Justice Ministry, the paper said Sharon and his son Gilad are suspected of receiving bribes, committing breach of trust, fraud, and deceiving the police and Israel's state comptroller.

At a news conference, Sharon adviser Eyal Arad denied wrongdoing by Sharon. He warned against "an attempt to bring down a prime minister and change the regime in Israel by means of a campaign of leaks, lies and disinformation."

The allegations concern a reported $1.5 million money transfer a made a year ago by South African Cyril Kern to the premier's sons, Gilad and Omri.

The money was used as collateral for a loan to cover the return of illegal campaign funds from the 1999 election, the report said, but Sharon let the impression stand that he had mortgaged his ranch instead.

An indictment would force Sharon to step down, but it appeared that the police investigation was far from completion. Instead, Sharon supporters charged that the report was a campaign ploy.

Polls show that Sharon's Likud Party is leading but losing altitude, partly because of charges of corruption and organized crime involvement in the Likud Party's selection of its parliament candidates.

The burgeoning scandals played no part in the first night of TV campaigning on Tuesday. In Israel, TV ads are limited to the end of the campaign and are concentrated into daily blocks of time on TV and radio stations.

There were the expected appeals from Sharon, explaining why he should be the one to conduct negotiations with the Palestinians, and his chief rival, Amram Mitzna of Labor, insisting that only a plan for separation from the Palestinians will work.

Each party presented a jingle with a popular music line. "We believe you, Mitzna, because only you can (do it)," crooned the Labor ad, while Likud singers countered, "people want peace and experience, people want Likud, people want Sharon."

Missing from the campaign spots was extensive use of pictures from Palestinian terror attacks.

The only picture of an attack -- a bombed-out bus -- appeared on a spot for Likud, Sharon's party, just before Defense Minister Shaul Mofaz warned voters that the fight against terrorism would be a marathon, not a sprint.

There was no mention of Sunday's attacks, in which two bombers blew themselves up in an old area of Tel Aviv crowded with foreign workers. The explosions ripped through a Chinese takeout restaurant, a pub and several shops.

Though the conflict with the Palestinians has steadily escalated during Sharon's two years in power, taking ever-increasing casualties on both sides, Likud presented itself as the party that can work best for security, with Sharon calling Mitzna a "raw recruit" when it comes to negotiations.

In the past, upsurges in terrorism have helped hard-line parties like Likud. Labor was hoping to counter the trend, pledging to build a fence between Israel and the Palestinians, pull out of Gaza and define Israel's border with the West Bank unilaterally if negotiations fail.

Under the Israeli system, voters pick a party, not a candidate for prime minister. The party leader who can form a majority coalition in the parliament becomes prime minister.

On the first night of TV campaigning, the dovish Meretz Party offered a jingle in a rap format and showed the back of a man's head in front of a wall.

Each time his head dipped forward and hit the stone wall, a word popped up on the screen representing the Meretz view of the main problems facing Israel: violence, Jewish settlements, personal security, military reserve duty, unemployment, and "ultra-Orthodox extortion" -- a reference to government subsidies favoring ultra-Orthodox Jews.