Kedah Menteri Besar Mukhriz Mahathir has joined his father Dr Mahathir Mohamad in questioning Putrajaya's handling of controversial 1Malaysia Development Berhad (1MDB).

Specifically, Mukhriz zoomed in on the Finance Ministry which is led by Prime Minister Najib Abdul Razak, questioning why it had sold the Tun Razak Exchange land so cheaply to 1MDB in the first place.

This follows outrage over Tabung Haji having paid RM188.5 million for 1.56 acres of the 70-acre land owned by 1MDB, at roughly RM2,779 per square foot.

1MDB had purchased the entire 70 acres from the government for a mere RM194.1 million (at roughly RM74.2 per square foot).

"If Tabung Haji is willing to pay such a high price for land belonging to 1MDB, what is the Finance Ministry's excuse to sell it at such a cheap price to 1MDB in the first place?" asked Mukhriz in a Twitter posting today.

Mahathir, who is former prime minister, was among the earliest and fiercest critics of 1MDB which has mustered a staggering debt of RM42 billion.

However, his criticism, particularly over 1MDB's questionable but complicated deals, have failed to gain traction until very recently, following Tabung Haji's purchase of 1MDB's land which is seen as a bailout of the debt-ridden company.

Tabung Haji is a fund largely made up of contributions from village folk, which is Umno's core support base, for the purpose of funding their pilgrimages to Mecca.