A wealthy businessman says his former "wife" is not entitled to a share in a £1.1 billion fortune because they were never legally married.

Asif Aziz, who is in his 40s, says he and Tagilde Aziz, who were both born abroad, obtained a "fake" marriage certificate so a child they had adopted could get a passport.

He wants a High Court judge to rescind a divorce pronouncement.

Mrs Aziz, who is in her 50s, disputes his claim and says they were married.

She says they were together for 20 years and she is entitled to a "fair share" of the marital pot.

Mr Justice Moor is analysing evidence at hearing in the Family Division of the High Court in London.

Lawyers say Mr Aziz comes from Malawi and Mrs Aziz is of Angolan-Portuguese descent.

Richard Harrison QC, for Mr Aziz, told Mr Justice Moor that Mrs Aziz said a Muslim ceremony of marriage had taken place in Malawi in 2002.

But he said Mr Aziz's case was that no ceremony took place and that a fake marriage "certificate of convenience" had been issued.

He said the marriage certificate was procured in order to obtain a UK passport for a child they had informally adopted.

"Mr Aziz's evidence is clear," Mr Harrison told the judge in a written case outline.

"The parties went on holiday to Malawi in September 2002.

"They were at that time planning to relocate to England.

"They needed a passport."

He added: "Arrangements were made."

Deborah Bangay QC, for Mrs Aziz, accused Mr Aziz of mounting an ambush.

She said he was determined to ensure that Mrs Aziz should not receive "any entitlement".

"Mrs Aziz is entitled to - and does - rely on the presumption of marriage and the facts that the parties presented to the world for the totality of the period between 2002 and their separation," she said.

"It is for Mr Aziz credibly to explain ... why he presented to the world for a period of two decades that he and Mrs Aziz were married."

She said an "unopposed" decree nisi had been pronounced by a judge in England in November 2016 and added: "The court need look no further than Mr Aziz's obvious determination to an achieve overwhelming victory over Mrs Aziz at any cost."

Mrs Aziz had "sought actively" to progress claims for a "fair share out of total resources of £1.1 billion", Mr Justice Moor was told.

Her lawyers said Mr Aziz had also argued that he had "no capital" and was a "man of straw".

Lawyers said outside court that Mr Aziz was the founder of London-based property business Criterion Capital The hearing is due to continue on Thursday.

Mr Justice Moor indicated that he would decide whether the marriage was valid before making any decisions on how much money Mrs Aziz should walk away with.

The hearing continues.