Love isn't all you need. Sometimes keys help, too.

Police were called to the London home of Paul McCartney Monday evening after staffers mistook the rocker's estranged wife, Heather Mills McCartney, for an intruder after spotting her security guard scaling the walls of the ex-Beatles' estate.

Mills McCartney had arrived at their formerly shared North London home as part of an arranged visit to pass off custody of the duo's two-year-old daughter, Beatrice, only to discover that McCartney had the locks changed since her last pop-in, which had been portrayed in British media reports as acrimonious.

McCartney was not home at the time of the incident, but his longtime staff, who presumably would have recognized the former missus, were.

According to the Daily Mirror, the 38-year-old landmine activist arrived at the home and spent nearly five minutes trying to unlock the estate's gates before retreating to her car while her driver tried to make contact with the staff through the intercom.

When nobody responded, Mills McCartney dispatched her security guard to scale the walls surrounding the home so as to unlock the gates from the inside.

After spotting the man attempting to climb the gates, McCartney's security, failing to recognize Mills McCartney's man, called police to report that an intruder was trying to enter the home.

"Police were called at approximately 7:50 p.m. to an address in [St. John's Wood] to reports of a suspect on the premises," a Scotland Yard spokesman confirmed.

"Officers attended and spoke to a female who subsequently left the scene. No offenses took place."

When police arrived, they immediately recognized Mills McCartney--about time someone did--and made her wait outside the home while other officers spoke with house staff. According to the Mirror, during the police inquiry, she took her daughter for a drive around the block so the girl wouldn't be upset by the swarm of cops on the scene.

When the mix-up was finally sorted out, the former model was allowed into the home, where she spent the night with her daughter. McCartney was due to arrive at the estate later today.

Mills McCartney's spokesman, Phil Hall, confirmed the incident, but said it wasn't as dramatic as the press has made it out to be.

"She was laughing about it," he told Reuters.

Whether the incident was simply a misunderstanding or a particularly cunning exercise in public humiliation, the lockout was just the latest episode in the duo's increasingly bitter and publicly played out divorce.

Last week, McCartney waged the latest battle against Mills McCartney, freezing their joint bank account after reportedly discovering that the missus had withdrawn nearly 1 million pounds in less than a month.

Her spokesman also confirmed that the account had been frozen, but denied that his client had withdrawn such "obscene" amounts of money.

The pettiness reached new heights again last week when McCartney had his lawyer fire off an angry legal letter complaining that three bottles of cleaning solution had been taken from his Sussex home to clean his estranged spouse's nearby office.

The duo announced their split in May after seven years together and proceedings have gone from treacly amicable--they stressed their continued respect and admiration for each other in the separation announcement--to nearly outright contempt.

McCartney blamed his wife's "unreasonable behavior" in his court filings, claiming she was argumentative and rude to his staff, and since then, Mills McCartney has borne the brunt of the tabloid coverage, with the newspapers printing salacious photographs of her early modeling days and accusing her of participating in pornography.

McCartney came to her defense after one tabloid went so far as to allege that she was a hooker in her early 20s, which resulted in her filing suit against the paper. McCartney, though, has not spoken publicly on the reports since June.

As for the divorce, a settlement may still be a long time coming. The couple failed to sign a prenuptial agreement before marrying, which means the lion's share of McCartney's 850 million pound fortune--roughly $1.6 billion--is potentially up for grabs.

The estranged spouses are hunkering down for a fight, having hired the same divorce lawyers as Prince Charles and Princess Diana. Anthony Julius, who represented Diana, will run point for Mills McCartney, while Fiona Shackleton, who was Charles' legal eagle, will advocate for McCartney.