Parts of a defunct German research satellite have returned to Earth and likely fallen into the Bay of Bengal, east of India, the chair of the German Aerospace Centre says.

Johann Dietrich-Woerner told CBC News on Sunday that the biggest piece could be 1.6 metric tonnes.

Scientists have been trying to establish how and where the satellite returned to the Earth, after warning that some parts might survive re-entry and crash at up to 450 kilometres per hour.

There was no immediate solid evidence to determine where exactly the satellite entered the atmosphere, indicating it did not hit a populated area, said Andreas Schuetz, spokesman for the German Aerospace Center.

But Dietrich-Woerner said scientists at the centre now believe it fell between India and Indonesia.

Most parts of the minivan-sized satellite were expected to burn up. The centre said the satellite entered the atmosphere Saturday between 9:45 p.m. and 10:15 p.m. EDT and would have taken only 10 or 15 minutes to hit.

Schuetz said it could take days to determine exactly where pieces of the satellite had fallen.

"I don't think that we'll have a confirmation of any sort today," he said, pointing out that it also took NASA several days to establish where one of its satellites had hit last month.

Scientists said hours before the re-entry into the atmosphere that the satellite was not expected to hit over Europe, Africa or Australia.

According to a precalculated path it could have been above Asia, possibly China, at the time of its re-entry, but Schuetz said he could not confirm that.