Housing officers conspired to unlawfully evict a Sudanese refugee from his council flat and destroy his possessions, including memory sticks holding thousands of hours of work, before then covering up their wrongdoing, a judge has ruled.

The victim, who was granted British citizenship after fleeing Sudan’s civil war in 1985, was made homeless for a year and forced to sleep on the streets after officials acting for Southwark Borough Council entered his home while he attended a court hearing in April last year over rent arrears of £18 per week.

All his possessions, including his passport, credit cards, furniture and computer equipment containing several years of research and personal material, were removed on the day of the eviction and destroyed in a waste disposal facility.

In a swingeing ruling, a High Court judge found that housing officers entered into a conspiracy to “harm” the man, known only as AA, by securing his eviction from his flat in Peckham, south London, and then conceal their actions from investigators.

Judge Anthony Thornton QC said: “The various officers conspired to evict AA by unlawful means, to seize and destroy his possessions by unlawful means and to cause him harm and loss by evicting him and dispossessing him of his possessions.”

In his own complaint, AA, who had sought £2.4m in damages, said he felt he had been “robbed of my dignity and pride” by the local authority.

Southwark, which is London’s largest social landlord with 40,000 properties, and which bills itself as providing a “great place” for its tenants to live, admitted that it had “got things very wrong” when dealing with AA.

But the local authority refused to say whether three officials singled out for particular criticism - income officer Christiana Okwara, her line manager Brian Davis, and resident officer Johanna Ashley - were still employed.

The decision to evict AA, who had been a council tenant for 23 years, and previously ran a charity helping children in Sudan, was the culmination of a lengthy process during which he had fallen into arrears on his rent due to an £18 shortfall between his housing benefit and the sum due to the local authority.

By the time of his eviction, which the council said followed multiple attempts to reach an arrangement to make up the deficit, AA owed £2,353 in unpaid rent.

The High Court ruled that by early 2013, Mr Davis and Ms Okwara had become determined to have AA removed from his flat and had a motive which was “eviction at all costs”.

Procedures for securing evictions, including obtaining permission from a judge to start proceedings, were not followed and a requirement that all flat clearances take place in the presence of two council officers was ignored, the judgment said.

Added to the fact that Ms Ashley knew AA’s possessions, which were of “incalculable and personal value” to him, were at risk of being destroyed, it was clear that the actions of the three officers made them liable for “misfeasance in public office” or the misuse or abuse of power, the court found.

Judge Thornton said: “They each acted with the intention of harming AA by evicting him when there were no reasonable grounds for evicting him and by arranging for his possessions to be seized and destroyed unlawfully.”

Southwark Borough Council, which had originally offered AA £6,400 in compensation for the destruction of his belongings, said it had reached an out-of-court settlement with the man.

Councillor Richard Livingstone, a cabinet member for housing, said: “We realise we got things very wrong when dealing with this person and their possessions. We have apologised for any distress we may have caused. We acted swiftly and took strong disciplinary action against our staff when this came to our attention.”