Redknapp's defence QC suggested that information was leaked from the City of London police to sports journalist Rob Beasley
The senior detective shouted at by Harry Redknapp for "staring" had faced accusations police were leaking details of the case to the News of the World.
The now defunct Sunday tabloid's conversations with both Redknapp and his co-accused, Milan Mandaric, formed a central part of the prosecution.
But the defence QC John Kelsey-Fry attempted to get the evidence thrown out, claiming the "press is effectively conducting a satellite investigation".
Both Detective Inspector Dave Manley and the sports journalist Rob Beasley denied City of London police was the "source".
Beasley instead said he paid several thousand pounds to someone close to Redknapp.
There had been simmering tension between the Tottenham Hotspur manager and officers since a dawn raid on his Dorset home that was watched by press photographers.
Redknapp told how his wife, Sandra, thought he must have been killed in a plane crash after looking out of the window to see the flashbulbs of photographers.
The manager was further enraged by the volume of information Beasley had obtained when they spoke to each other on the eve of the 2009 League Cup final between Spurs and Manchester United.
Kelsey-Fry said during legal argument that Beasley's intentions were "repugnant".
But during evidence heard in the absence of the jury, the judge, Anthony Leonard, dismissed the QC's submissions that the evidence was "evasive, contradictory and manifestly unreliable".
The judge also ruled out a later bid by Kelsey-Fry to have the case thrown out altogether.
During questioning with Manley, a senior officer on the case, the barrister said: "It is, I suggest, blindingly obvious that there was a leak from your organisation, from somewhere within your investigating authority."
Manley replied: "I would like to find out what happened. I would like to know that information. It remains a mystery. People in football talk to the media on a daily basis."
Kelsey-Fry added: "Mr Beasley told the court that he believed that both Mr Mandaric and Mr Redknapp were actually under investigation and subject to an ongoing investigation, and he was going to interview them on what he understood to be the same matter.
"There is a distance between what they said in interviews with police and what evidence is brought and what they mentioned subsequently. The evidence is simply overwhelming.
"Mr Beasley's evidence cannot properly be relied upon. It's evasive, contradictory and manifestly unreliable. I can't find any other situation where the press is effectively conducting a satellite investigation.
"The reality is that Mr Beasley is very much better informed about what was going on than they were. What he set out to do is not only unattractive, it is quite ? repugnant."
While he was giving evidence, Redknapp shouted at Manley.
Gesturing across the courtroom, Redknapp said: "Mr Manley, will you please stop staring at me. I know you are trying to cause me a problem, OK."