Kolopita was released hours later and sent to hospital.
He said the four men beat and kicked him in a police car while he was still handcuffed.
"I was helpless as I was hit and kicked in the pit of my stomach, chest and abdomen," he said.
The Indonesian karate team boycotted the tournament and flew home following the incident which occurred last Friday.
The four policemen said Kolopita was behaving suspiciously, and tried to punch them and run away when they questioned him, Malaysian media reported.
|Hundreds protested outside the Malaysian |
embassy in Jakarta [AFP]
In Kuala Lumpur an embassy official, Tatang Razak, said the karate coach had thought the four men were robbers.
"He was very shocked. Of course, he is a karate coach, so he fought back," he said. "What happened was unbelievable. Kolopita was tortured by the police."
Another embassy official said Kolopita was hospitalised in a Jakarta hospital with broken ribs and swelling of his face and genitals.
On Tuesday, a Malaysian delegation led by Syed Hamid Albar, the foreign minister, offered a public apology to the Indonesian president during a meeting in Jakarta.
Susilo Bambang Yudhoyono, the Indonesian president, said the government appreciated the Malaysian government's responsibility and commitment to pursue the case legally.
"I certainly appreciate [Malaysia's] commitment because, after all, it is a quite serious case. An inappropriate and excessive thing has happened," he said.
He added: "Therefore, I want the law and justice upheld. This is what I conveyed to the Malaysian foreign minister and police chief."
Musa Hassan, the Malaysian federal police chief who was also present, was quoted in the New Straits Times as saying he was "taking a personal interest" in the case and had "ordered a thorough investigation".
Indonesians have protested several times in recent months over reported cases of abuse against Indonesian maids in Malaysia.