He was one of General Franco's most feared enforcers, accused of brutally beating political prisoners including pregnant women during his time in the secret police.

But Antonio González Pacheco, better known as “Billy El Niño” (Billy the Kid), may finally feel the heat when he is stripped of his police honours and bumper state pension by Spain's new Leftist government.

Spanish Prime Minister Pedro Sánchez will on Sunday present the members of the country’s hardest Left government since the end of the dictatorship in the mid-1970s.

As well as tax-and-spend policies and social reforms, the coalition of the anti-austerity Podemos and the Communist parties with Mr Sánchez’s Socialist PSOE has drawn up extensive plans to dismantle the remaining vestiges of the Franco regime.

After last October’s move by Mr Sánchez to exhume the remains of General Franco from the Valley of the Fallen monumental mausoleum, the prime minister’s PSOE and the Unidas Podemos leftist bloc agreed in their coalition programme to take what they call the “democratic memory” agenda into new areas.