A sister of murdered Belfast man Robert McCartney has said the family will not be used for political means.
Two of the sisters refused to collect the award in London
Catherine McCartney was speaking after refusing to share a platform with Margaret Thatcher, claiming she had "inflicted injuries" on Ireland.
She and sister Claire were expected to collect an award along with the former prime minster at a London ceremony.
However, former aide Sir Bernard Ingham criticised the sisters, describing their action as "a grand gesture".
Mr McCartney, 33, was stabbed to death outside a Belfast bar in January. Two men have been charged over his murder.
Mr McCartney's family have campaigned for justice for their murdered brother and claim they have been intimidated by the IRA.
Lady Thatcher was honoured at the awards
Catherine said the sisters only discovered that Baroness Thatcher was present when they arrived at the Guildhall on Thursday.
She said they made an immediate decision not to take part in the awards ceremony.
"Our campaign is one of justice and our main focus is our brother Robert and the injustice that happened to him and to our family since January," she told BBC News on Friday.
"But in the same way, we cannot ignore other injustices that have been carried out and we felt it wasn't possible to share a platform with someone we would certainly identify with carrying out injustices in Ireland against our own people.
"We weren't aware of who else was receiving awards. That was part of the protocol of the event - that award winners did not know who else was receiving an award."
She said the event organisers were well-intentioned and had acted in good faith.
"They were very understanding when we explained our situation and we fully appreciate their support and the recognition that they did give us."
The family said they would not be used by any group for political means.
Sir Bernard said Baroness Thatcher did not need to apologise
However, former Downing Street press officer Sir Bernard Ingham said: "Justice is indivisible - you can't have justice for one and no justice for other people," he said.
On the McCartneys' refusal to accept the award, he believed Baroness Thatcher "would not grace it with any comment" and had nothing to apologise for over her conduct as prime minister.
Members of the McCartney family are expected to travel to Washington within the next few weeks to meet Senator Edward Kennedy.
In March, they had separate meetings with Mr Kennedy and President George Bush, both of whom refused to meet Sinn Fein President Gerry Adams at the time.