Families stopping to talk on the street would be in violation of the six-limit rule, the interior minister has said.
Priti Patel told the BBC that two families of four who stopped for a chat on the way to the park “interfered”
She said she would report her neighbors if they broke the rules.
The rules restrict indoor and outdoor gatherings in England and Scotland and indoor groups in Wales.
The new measures mean police can break up groups larger than six with fines of up to £ 3,200 if people break the rules.
In a speech to BBC Radio 4’s Today program, Mrs Patel said two families of four who stopped for a chat on their way to the park were “completely mixed”.
“You have to put this in the context of coronavirus and keep your distance, wearing masks,” she said.
“The rule of six is about ensuring that people are conscientious and do not endanger the health of others.”
The Home Secretary added: “Mingling is people coming together. That is my definition of mingling.”
Asked if she would call police on her neighbors if they violated the new rules for coronavirus, Mrs Patel told BBC Breakfast: “I do not spend my time looking into people’s gardens.”
Pressed further on the subject, she said anyone would want to “take responsibility” for helping stop the spread of the virus, adding that if she saw collections of more than six, “I would clearly report it”.
Mrs Patel’s comments repeat those of Police Minister Kit Malthouse who suggested that people should call the non-emergency 101 number if they were concerned that people were breaking the law.
It comes as the national chairman of the Police Federation of England and Wales called for guidance on enforcing the measures.
Speaking to Good Morning Britain, John Apter said that frontline police officers “tried to interpret” the rules and were accused of “asking (people) to sneak up on their neighbors”.
He added: “Maybe we should have guidance because we haven’t had any yet.”
Government guidelines include exemptions for physical activities that can be performed in groups of more than six, such as football, hockey and netball, as well as sailing, angling and polo.
Shooting – including hunting and paintball, which requires a license for a shotgun or firearm – is also exempt as an organized sport.
Earlier, Mrs Patel defended the government’s record of probation following widespread reports of people struggling to be whipped.
She told BBC Breakfast that the government “increased capacity” where needed.
“There is clearly a lot more work to be done with Public Health England and the actual public health agencies in the particular local areas, and as a government we are obviously working with Public Health England to increase where there is demand in local hotspot areas. “
Health Secretary Matt Hancock has said the system faces a “huge challenge” after a “sharp rise” in people seeking a test. He said it would take a matter of weeks to resolve the issues.