TOKYO -- A Japanese court officially declared a man innocent Friday in the murder of a 4-year-old girl and offered a rare apology for a forced confession and wrongful conviction that kept him behind bars for more than 17 years.

Toshikazu Sugaya, 63, was serving a life sentence when new DNA tests last year showed his innocence. He was immediately released from a jail in Chiba, east of Tokyo.

Friday's verdict in his retrial, which opened in October, officially cleared Sugaya and confirmed that the flawed earlier DNA tests and a questionable investigation had pressured him into making a false confession.

"I won an immaculate innocent ruling," Sugaya said. He waved to supporters as he walked out of the court and then broke down in tears. "I've been waiting so long for this day."

The case has prompted calls by rights groups and lawyers to speed up the introduction of full recordings of interrogations to prevent forced confessions and other problems. Japanese investigators have long been criticized for questioning suspects for lengthy periods without immediate access to lawyers.

"I feel deeply sorry as a judge that we failed to listen to Mr. Sugaya's true voice and as a result took away your freedom for 17 1/2 long years," presiding Judge Masanobu Sato said in the unusual apology at the end of the ruling. "As I realize the irreversible damage we have caused, I renew my commitment not to repeat the same mistake."

The other judges also stood up and bowed in apology to Sugaya, who later said he accepted their apology.

Local police and prosecutors apologized to Sugaya earlier.

Utsunomiya District Court spokesman Masahiko Otake said prosecutors would not appeal Friday's ruling, making it final.

Sugaya, then a kindergarten bus driver, was arrested in late 1991 in the murder of a 4-year-old girl in Tochigi, north of Tokyo, a year earlier. A local court sentenced him to life imprisonment in 1993, and Japan's top court rejected his appeal in 2000.

Sugaya was arrested based on the earlier DNA tests, but his lawyers repeatedly questioned the accuracy of the results and demanded new tests. The Tokyo High Court in 2008 approved new DNA tests which were conducted in January 2009.

The new test results did not match Sugaya with dried body fluid on the girl's clothing, contradicting the initial tests. No new suspect has been identified.

"The fog in my heart won't completely clear until the real culprit is caught," Sugaya said.