The Guardian has won another award for its reporting on the Windrush scandal, this time at the Amnesty media awards.

Kate Allen, the director of Amnesty International UK, presented the Impact award at a ceremony at Bafta in central London on Wednesday night to the Guardian reporter Amelia Gentleman, who spearheaded the investigation into the Home Office’s mistaken classification of thousands of long-term British residents as illegal immigrants.

Amelia Gentleman at the Amnesty International media awards at Bafta in central London. Photograph: Amnesty/Twitter

After six months of reports about individual Windrush cases in the Guardian, the prime minister was forced to apologise in April last year for the hurt caused to victims, while the then home secretary, Amber Rudd, said she was sorry for the “appalling” actions of her own department and resigned that month after admitting she had inadvertently misled parliament.

On Wednesday the home secretary, Sajid Javid, announced that the government would pay up to £200m in compensation to people whose lives were damaged by the scandal.

“Nothing we say or do will ever wipe away the hurt, the trauma, the loss that should never have been suffered by the men and women of the Windrush generation, but together we can begin to right the wrongs of Windrush,” Javid said.

The Amnesty award is one of many received by Gentleman and the Guardian for their Windrush coverage. On Tuesday night, the investigation won the Cudlipp award for campaign of the year at the National Press Awards.

In December Gentleman was named journalist of the year at the British Journalism Awards in London for her work on the Windrush scandal, with judges describing her work as “astonishing”, adding: “It set the agenda for weeks and brought down a home secretary (even though the policy came straight from Mrs May). The detail and the case studies were brilliant and everyone followed this story up.”

Gentleman also won the prestigious Paul Foot award last June for her reporting on Windrush.