Around 30 Indian software professionals have left Malaysia, saying they were mistreated during a police raid, and scores more were preparing to go as well, Malaysia's opposition leader and the Indian ambassador said on Thursday.

Police last Sunday initially ordered 270 Indians out of a high rise apartment building, and then herded some 160, many of them handcuffed, into the police compound and a garage, where they had to wait for hours before most of them were freed.

Less than ten were detained for passport irregularities in a police operation against illegal workers.

The incident has damaged both Malaysia's ambitions to build a reputation in the information technology industry and its diplomatic ties with an increasingly important trading partner.

Lim Kit Siang, leader of the opposition Democratic Action Party, lodged a report slamming the police with Malaysia's human rights body Sukaham, and met several of the Indians involved.

"They feel that they are not safe (staying in Malaysia) after their harrowing experience. Some of them had been here for two years," Lim told Reuters.

He said around 30 of them have already left the country and another 100 were preparing to leave by the end of the month.

India lodged a protest with the Malaysian government over the conduct of its police.

Kuala Lumpur's police chief Dell Akhbar Khan said on Thursday he had made a probe into the incident a top priority.

India's High Commissioner to Kuala Lumpur Veena Sikri said many of the Indians caught up in the raid were quitting their jobs and going home.

"Many more have made bookings for departure in the next two or three days," Sikri said.

She estimated there are at least two thousand Indians working as computer specialists in Malaysia, though figures are unreliable as few have registered with the High Commission.

Short of skilled IT workers, Malaysia has sought to tap India's computer savvy labour pool to help its Multi-media Super Corridor hi-tech zone take off.

"As far as the MSC is concerned, I would like to reassure them that we continue to welcome and value the contributions of Indian nationals in our IT industry," Leo Moggie, Malaysia's communications and multimedia minister said at a function on Thursday morning.