For Tun Dr Mahathir Mohamad, there is something 'suspicious' in the alleged doctored emails exchanged between PetroSaudi International and 1Malaysia Development Berhad (1MDB).

"Anyone can intercept an email these days. Looking at the series of emails exchanged, there is something suspicious," the former premier said.

Asked if he would apologise to Prime Minister Datuk Seri Najib Razak should the leaked documents regarding 1MDB turn out to be false, he said he would assess the situation then.

"I will have to see everything first," he answered curtly.

On talks between him and Najib thawing their frosty relationship during the holy month of Ramadan, Dr Mahathir said these issues were not personal.

"We can meet and chit-chat and shake hands but the crux of the matter must be solved.

"It is the people's money we are talking about here," Dr Mahathir told reporters after a 'buka puasa' do organised by Pertubuhan Pribumi Perkasa Malaysia (Perkasa) in Kampung Baru here tonight.

On Monday, it was reported that a former PetroSaudi staff, Xavier Justo, was arrested by Thai police at his home in Koh Samui, Thailand for allegedly blackmailing and extorting PetroSaudi pertaining to its deal with 1MDB.

It is believed that Justo, a 49-year-old a Swiss national, was the one who had leaked information on 1MDB to UK-based Sarawak Report on apparent mismanagement and misuse of government funds.

READ: 1MDB: "It'd be nice if PAC can get a statement from Justo" - Nur Jazlan

READ: Arrest of ex-PetroSaudi staff won't jeopardise 1MDB probe - PAC

READ: Emails leaked by ex-PetroSaudi staff tampered with - 1MDB