Tony Blair gives a speech at Peking University in Beijing, China.
Tony Blair gives a speech at Peking University in Beijing, China. Reuters

Former British prime minister Tony Blair netted £13m from his business interests following his most commercially successful financial year since leaving Downing Street.

The accounts for the 12 months to April 2013, which were lodged at Companies House last week, reveal that Blair's global network of businesses is booming, with profits at one company totalling almost £2m.

The Sunday Telegraph reported that shareholder funds on two of Blair's businesses total £7m, taking his overall wealth to an estimated £70m.

The former British premier administers his vast commercial empire through a complex series of companies and partnerships headed by two businesses – Firerush Ventures Limited and Windrush Ventures Limited.

Firerush Ventures administers the funding for Blair and his team's work advising sovereign wealth funds and various companies, while Windrush Ventures is understood to channel money for Blair's government advisory practice, which provides national governments with policy advice.

The accounts for Windrush reveal a turnover of £14.9m for the 12 months to April 1 2013 and a profit after tax of nearly £2m – a £650,000 rise on the previous year. Cash in the bank and "in hand" funds totalled £8.8m – a rise from £1.5m the previous year.

These numbers are a big improvement on last year. Mr Blair has had a very good year
City of London accountant

Windrush paid corporation tax on its profits of £653,000. Although the company's turnover totalled nearly £15m, it paid tax on only a fraction of that figure because £12.1m was paid out in expenses to cover the cost of office rents, travel and hotel bills for Blair and his team.

"These numbers are a big improvement on last year," one City of London accountant told the Sunday Telegraph. "Mr Blair has had a very good year. This is a bumper year – his best year yet."

The figures show that Blair lent his own company £1.24m in 2012 at a commercial rate of 5.5%. The loan was repaid to Blair in December 2012 with "applicable loan interest", earning the former PM £75,000 over the course of the year.

Blair has earned a fortune since leaving office in 2007. He is an official adviser to investment bank JP Morgan and Swiss-based global insurance company Zurich International, and flies around the world in a £30m chartered private jet.

Blair's successful post-government career includes providing advice to wealthy nations such as energy-rich Kazakhstan, whose autocratic ruler Nursultan Nazarbayev is accused of human rights abuses.

Blair's dealings with Kazakhstan have been criticised, but the former PM says he uses the profits from his commercial ventures to fund his philanthropic activities, which include a faith foundation and a non-profit organisation that advises African governments.