AN SAS commander who helped bring an end to the six-day Iranian Embassy siege in London has died aged 71.

Tom MacDonald, who was born in Glasgow on October 1, 1948, passed away after a battle with cancer on Monday.

He began his military career as both a part-time and full-time soldier in the British Army's parachute regiment, before joining the SAS from the mid 1960s until 1995.

MacDonald lead a four-man sniper team back in 1980 - when six armed members of the Arabs of KSA group stormed the central London building on April 30, taking 26 hostages.

The SAS took back the building on May 5 after the killing of a hostage, with the operation broadcast live on television from the streets below.

In his bid to end the siege, MacDonald killed two terrorists in quick succession as they swooped through the South Kensington block.

The only surviving terrorist, Fowzi Nejad, spent 28 years before he became eligible for parole in 2015.

The commander, who retired to New Zealand in 2003, told the local Otago Daily Times back in April: "The whole thing lasted minutes.

"When we went into the embassy it was on five floors. My snipers were meant to contain the first floor, where I was, and the fifth floor, and the assault team were to take the middle three floors.

"It turned out that a couple of the terrorists had come down to the floor that I went in on. It was me that jumped the balcony and went in through the front window, myself and another three.

"We found the terrorists in there and dealt with them, so within 30 seconds I had gone through a window and killed two people, which wasn't really expected."

Before his death, the veteran is said to have regularly travelled to the UK to visit the graves of his fallen comrades at St Martin's Church in Hereford.

Following the operation he was awarded the Queen's Gallantry Medal, and it is said that he and his men shared a beer with then Prime Minister Margaret Thatcher.