The police have opened four investigation papers against former premier Dr Mahathir Mohamad, said inspector-general of police (IGP) Khalid Abu Bakar today.

However, he would not confirm if any concerns the ex-premier’s latest call for foreign intervention.

"We have already opened up four investigation papers against Mahathir.

"Some are incomplete and some are being discussed with the attorney-general (Mohamad Apandi Ali)," Khalid told reporters during a press conference after attending a police promotion ceremony at Bukit Aman this morning.

"Some (investigations) are for sedition and some for other things. No decisions have been made so far," he added.

Khalid said this when asked whether police are investigating Mahathir over his latest remarks as reported by The Australian on Saturday, urging for foreign intervention to oust prime minister Najib Abdul Razak.

Among others, the Umno Veterans Club have urged that action be taken against Mahathir under the Sedition Act for trying to bring in foreign interference into the administration of the country.

Its secretary Mustapha Yaakub reportedly said that the former prime minister had gone overboard, a clear indication that he was desperate in his attempts to overthrow Najib.

On March 29, Deputy Home Minister Nur Jazlan Mohamed had also said that police are probing Mahathir’s offer to secure asylum for wanted former police commando Sirul Azhar Umar.

In February, several police reports were also lodged against Mahathir over his blog posting that repeated urgings for Najib's resignation, on grounds that 1MDB-linked financial scandals had shamed the country.

Mahathir also slammed Apandi for allegedly protecting Najib.

In the blog posting, he also expressed doubts about Apandi’s willingness to cooperate with his Swiss counterpart on the European country's investigation into 1MDB.