German news magazine Der Spiegel – citing documents from soccer whistleblowing platform Football Leaks said Becker struck the deal in 2013, which contributed to his recent bankruptcy.
Spiegel claimed the ‘mega-deal’ was brokered by a Canadian firm and a Nigerian employee of Becker, pictured.
In the report, documents show that in July 2013 Becker held shares in an oil and petrol firm in Nigeria. But the investments tanked and last month he was declared bankrupt.
According to the German news magazine, John Briggs, Becker’s lawyer, told the London court: ‘He is not a sophisticated individual when it comes to finances.’
The 49-year-old who was once estimated to be worth upwards of £100million, was declared bankrupt over undisclosed sums owed to London-based private bankers Arbuthnot Latham & Co since 2015.
His remaining assets, according to the report will be disposed of to pay creditors.
In 2001, Becker landed with divorce and paternity settlements totalling more than £20million to his first wife, Barbara, and Angela Ermakova, the Russian model who had his baby after a brief encounter in a London restaurant.
The following year, he received a two-year suspended sentence for tax evasion. He was ordered to pay £2.5million in back tax, fines, and costs after claiming Monaco as his main residence while mostly living in Munich.
Boris Becker is a German former No.1 tennis player. He was successful from the start of his career, winning the first of his six major singles titles aged 17. He also won five year-end championships, 13 Masters Series titles, and an Olympic gold medal in doubles among many others.