David Cameron's official spokesman confirmed that the premier would be prepared to "make further representations" to the government there if it would help Scotland Yard's inquiry.
He said: "The Prime Minister and the Home Secretary and others have always been clear that they very much support the work that the British police authorities are doing in this and are always prepared to consider whether there is more that can be done and, as part of that, always stand by to make further representations to the Portuguese government for example if that would be helpful.
"Investigations are rightly for police authorities but if there is more that the Government can do to help facilitate, we would certainly consider that and look to do as much as we could to help."
Yesterday, Deputy Assistant Commissioner Martin Hewitt expressed frustration at the speed of the legal system through which UK police have to ask for Portuguese assistance with their inquiry. He said: "That's causing us frustration because we know what we want to do and we are ready to go with that. But the process is the process."
Scotland Yard has so far written three international letters of request to the Portuguese, covering 41 priority areas and including 287 separate requests.
Yesterday, Detective Chief Inspector Andy Redwood revealed that the force were looking for a lone intruder who sexually abused five British girls during a series of break-ins in the Algarve .
The tanned, dark-haired man is suspected of breaking in to 12 properties where British families were staying, between 2004 and 2010.