Police have warned anyone who sees Hussain not to approach him
The escape of a rapist being processed for deportation at the Pakistan High Commission has caused a diplomatic row.
Officials there have lodged a formal complaint that UK officials failed to alert staff that he was dangerous.
Police have been hunting for Imtiaz Hussain, 44, since he climbed out of a toilet window at the London embassy and escaped last Friday.
The UK Border Agency said it never commented on operational issues but the police were told immediately.
The convicted double rapist was brought under guard to obtain a passport so he could be deported at the end of a nine year prison sentence.
Syeda Sultana Rizvi, of the Pakistan High Commission, said a formal complaint had been made to the British authorities and accused immigration officials of failing to make an appointment and leaving the man inadequately guarded.
Mrs Rizvi said diplomatic staff only learned of his visit from panicking private security guards after he disappeared from the building.
She said: "Why did they bring him for the interview without prior information in the first place?
"And why was the criminal inadequately guarded?
"There are many questions that can be raised surrounding the entire episode."
Hussain was last seen running across Sloane Square, in west London, after escaping from the building in nearby Lowndes Square at about 1435 GMT last Friday.
Before escaping, he told private security guards from G4S Care and Justice Services that he needed to visit the toilet.
Hussain was approaching the end of a prison sentence after trying to rape two women at knifepoint in Derbyshire.
David Wood, of the UK Border Agency, said: "Police were immediately informed. His details have been placed on the Police National Computer and watch lists.
"We are actively searching for this individual to return him in to custody and remove him from the UK."
Det Ch Insp Brent Lancaster, of the Metropolitan Police, said: "This individual is believed to very dangerous and we need to apprehend him as soon as possible.
"If anyone sees him, please don't approach him, but call police immediately."
Officers were working with colleagues in Derbyshire to establish if Hussain had any contacts in Britain who may help him while on the run.
He was described as about 5ft 5in tall, of medium to chubby build with dark cropped hair. He was wearing a blue T-shirt, blue jeans and white trainers.