The frozen assets include homes in the US and Switzerland, a mega-yacht and three private jets. Kola Aluko sold a Bel-Air mansion last month for $21.5m

A court has frozen almost $1.8bn (£1.2bn) in assets owned by a pair of oil tycoons as Nigeria steps up its campaign to recoup tens of billions of dollars funnelled from state coffers under the regime of former president Goodluck Jonathan.

The order, handed down 10 days ago by the High Court in Lagos, offers a glimpse of the extraordinary lifestyle of Kola Aluko, 46 , and former business partner Jide Omokore. Both rose to fabulous wealth thanks to deals struck with Jonathan’s former oil minister, Diezani Alison-Madueke, who is also being investigated.

Among the assets that have been frozen are a $45m estate overlooking the Pacific in Santa Barbara, California, a 210ft mega-yacht called the Galactica Star , three private jets, a collection of 58 cars, homes in Switzerland, Beverly Hills and New York, and an equity stake in Seven Energy, a London-based gas producer that Aluko founded. The move is the latest sign of the net tightening around a coterie of businessmen and politicians from Jonathan’s five years in power, which ended with his defeat in last year’s election to Muhammadu Buhari.

An estimated $1bn a month disappeared during Jonathan’s rule, mostly in dodgy oil and gas deals. Buhari is leading an aggressive effort to recover the funds.

In October Alison-Madueke was arrested in London on “suspected bribery and money laundering offences”.

The National Crime Agency is also looking into Aluko’s affairs. It has asked the attorney- general of Switzerland, where Aluko is a citizen, for “mutual legal assistance”. Alison-Madueke, Omokore and Aluko have maintained their innocence. Aluko’s lawyer Rutsel Martha, the former general counsel of Interpol, declined to comment.

The legal fisticuffs come at a critical time for Nigeria. Africa’s biggest oil producer has been hit hard by the collapse in the price of crude. This week its finance minister will lead a delegation to London to sell investors on a multibillion-dollar bond to shore up its battered public finances.

The case against Aluko, Omokore and their company, Atlantic Energy, revolves around deals they struck to sell oil on behalf of Nigeria’s state producer. Rather than hand the proceeds to the state, the attorney-general argued that they, “unlawfully diverted . . . $1,762,338,184.40 to their private use.”

It highlighted a series of sales that Atlantic made to Glencore. The FTSE 100 commodities trader paid $811m for several tankers of crude. Aluko and Omokore then allegedly sent the proceeds “to several countries around the world for purchase of properties,vehicles and for investments rather than fulfil due obligations to the [state].”

Aluko last month sold his Bel-Air mansion for $21.5m. Nigeria said the order was necessary to prevent further liquidations.