The Swiss lawyer Enrico Monfrini hired by the Nigerian government since 1999 to recover state funds looted by the late military dictator Sani Abacha says his work has secured the restitution of more than $2.4 billion.

Mr Monfrini was contracted by the Obasanjo administration to help recover the looted funds.

The lawyer said Nigerian authorities provided him with valuable documents and he immediately contacted the Swiss attorney general who alerted all the banks in Switzerland.

He told the BBC in an interview that the Abacha family fought back, delaying the recovery process for years.

“The Abachas were fighting like dogs. They were appealing about everything we did. This delayed the process for a very long time,” he said.

Monfrini had agreed a commission of 4 per cent on the money sent back to Nigeria.

By 2018, the amount Switzerland had returned to Nigeria had reached more than $1bn.

Liechtenstein, in June 2014, sent Nigeria $277m.

The lawyer said some countries are yet to return the loot for fear of the funds being re-looted.

In May 2020, $308m held in accounts based in the Channel Island of Jersey was also returned to Nigeria following agreement that the money would be used, specifically, to help finance the construction of the Second Niger Bridge, the Lagos-Ibadan expressway and the Abuja-Kano road.

Monfrini said he is still expecting $30m in the UK to be returned, along with $144m in France and a further $18m in Jersey.

“At the beginning people said Abacha stole at least $4-$5bn. I don’t believe it was the case. I believe we more or less took the most, took a very large chunk, of what they had,” he said.

“They are not swimming in money like they used to do in the past.”