Najib Razak
Najib Razak has consistently denied allegations of corruption/AFP

The $681m (£479m) deposited in the bank account of Malaysian PM Najib Razak by Saudi Arabia was to help him win the 2013 elections, a Saudi source says. Malaysia’s attorney general cleared Mr Najib of allegations of corruption on Tuesday after ruling that the money was a donation from the Saudi royal family.

Mr Najib had denied that the money came from state investment fund 1MDB. The Saudi source said the donation was made amid concern in Riyadh about the influence of the Muslim Brotherhood. At the time, Malaysia’s opposition alliance included the Pan-Malaysian Islamic Party (PAS). Its founders were inspired by the Brotherhood, although there is little evidence the Brotherhood actually has much support in Malaysia.

Mr Najib’s coalition went on to win the election, but with one of its poorest showings in more than 50 years in power. The secretive donation to Mr Najib was allegedly paid over in several wire transfers between late March 2013 and early April 2013, just ahead of the election on 5 May.

The well-placed Saudi source, who has asked not to be named, told the BBC the payment was authorised from the very top – from Saudi Arabia’s late King Abdullah – with funds coming from both his personal finances and state funds.