The police are attempting to drill open a safe in former prime minister Najib Abdul Razak's residence on Jalan Langgak Duta in Kuala Lumpur, which has allegedly remained locked for two decades.

His lawyer Harpal Singh Grewal also claimed that the key has been misplaced.

"At about 8.30am, some of the officers proceeded to a room located on the first floor and decided to drill open the safe.

"There is absolutely no peace and quiet in his residence.

"The search conducted on the premises and the items seized thus far would seem of insignificant value and the continued presence of police officers in his residence and the drilling of the old safe strongly suggests unwarranted harassment,” Harpal told reporters.

This has caused mental distress and anguish to the former prime minister's family, staff and others in the house, Harpal said in a statement after emerging from Najib’s house this evening.

Asked by members of the press what was in the safe, the lawyer replied: "God knows."

Harpal also explained that the police had conducted the raid based on the Anti-Money Laundering Act 2001.

Asked what was carted out in the Black Maria that had left the house earlier, the lawyer answered that nothing significant had been seized.

“They took some boxes, some clothes and bags. What they have taken, to us is insignificant.

“Nothing, no documents were taken at all,” he said, adding that he did not recognise the man riding behind the truck.

Asked if Najib intended to press charges over the raid, Harpal did not answer but stressed that his client was “very unhappy” with what had transpired.

He also said about six or seven police officers still remained inside the house at the present moment.