A man and woman have been arrested on suspicion of murder over the deaths of a mother and her three children whose battered bodies were found in their home in Cheadle Hulme, Manchester.

In an unexpected twist in the case, the 35-year-old woman from Burnage, Manchester, was being questioned this morning by detectives investigating the murder of Uzma Rehan, 32, and her three children, whose bodies were discovered when police forced entry to the house on Sunday afternoon. They may have been dead for up to four weeks.

This afternoon, police announced they had made a second arrest, and were questioning a 40-year-old man also from the same area.

A Greater Manchester Police spokeswoman said: "Police investigating the murder of a woman and three children in Cheadle Hulme have this morning arrested a 35-year-old woman from Burnage on suspicion of murder. She remains in police custody and will be questioned by officers later today."

To date, the investigation had focused on Rahan Arshad, the husband and father of the victims who police believe may have fled to Pakistan several weeks before their bodies were found.

Police have mounted a international search for the 36-year-old taxi driver whose ?27,000 BMW sports car was discovered at Heathrow on Monday night. The vehicle had spent several weeks in a car park at Terminal 3, which has scheduled flights to the Indian sub-continent.

Detective Superintendent Martin Bottomley, of Greater Manchester Police, confirmed the two arrests, adding: "We are still actively looking for Rahan Arshad and I now believe that he left the country on around July 29. We will be liaising with our colleagues in international police forces to help us to trace him."

Post-mortem examinations carried out on Mrs Rehan?s children Adam, 11, Abbas, eight, and Henna, six, which were released this morning, concluded they had been beaten to death.

The post-mortem examination on Mrs Rehan had not yet taken place but the results of it were expected to be released later today.

Detectives said yesterday that they were making inquiries at the airport and with several airlines to establish whether Mr Arshad had flown from Heathrow during the past month. His wife, the daughter of a bank manager, was from Pakistan originally but came to Britain after marrying her husband in her home city of Lahore in 1992.

They lived initially in the Burnage area of South Manchester, where Mr Arshad was born into a wealthy family. His father is thought to have moved to Pakistan last year after the death of his wife.

Friends of Mrs Rehan have said that the couple?s arranged marriage was deeply troubled in recent years. She was attempting to forge a life as a modern woman, making friends outside the Muslim community and wanting to wear Western clothes and make-up.

One close friend said that Mr Arshad had been extremely jealous of his wife, who worked as a school dinner lady, and could be aggressive towards her at times.

The couple had previously separated but Mrs Rehan and the children moved back with her husband about a year ago after she decided to give their marriage a last chance. Their three children were pupils at Bradshaw Hall Primary School in Cheadle Hulme. 
 
 
 Jill Lowe, the school?s head teacher, described them as "lovely, confident, cheerful children" who made friends easily, joined in all the school?s activities and had a 100-per cent attendance record.

"Henna was a lovely, lively, bubbly six-year-old, as you would want any six-year-old to be," she said.

"Abbas loved his sport. He loved football and was straight out into the playground at break. He made lots of friends. Adam was a bright and happy boy who was due to start secondary school next month."

It is thought that the children and their mother may have been killed soon after the region?s primary schools broke up for the summer holidays.

Their bodies were removed from the end-of-terrace, four-bedroom house on Monday.They have not yet been identified formally and Greater Manchester Police have refused to disclose where in the house the bodies were found.

Detective Superintendent Martin Bottomley, who is leading the murder inquiry, said that police were in contact with the families of both Mr Arshad and Mrs Rehan, but had not yet spoken directly to any of their relatives in Pakistan.

The car found at Heathrow is being taken to Manchester for tests.