The BBC's National Lottery show was briefly delayed on Saturday evening after protesters invaded the studio and chanted slogans.
Presenter Eamonn Holmes was led from the stage as Fathers 4 Justice members made their way on to the set.
The National Lottery: Jet Set was delayed for several minutes before the draw for the £17m jackpot was resumed.
Campaign group Fathers 4 Justice said the evening marked the "dramatic return" of the protest group.
The group appeared to have disbanded in January after some of its members were accused of allegedly plotting to kidnap Prime Minister Tony Blair's youngest son, Leo.
Guy Harrison, a spokesman for the paternal rights group, said it was the group's duty to warn parents about family law.
Mr Harrison added: "The lottery is a metaphor for what can happen to any parent, mother or father, and their children, at the hands of the secret family courts."
Afterwards presenter Holmes said it had been a "scary moment".
Alan Dedicoat, the so-called voice of the National Lottery balls, told the BBC: "We just had a kerfuffle. What appeared to be fireworks or something going off in the studio.
"The cameras moved to one side. Eamonn was pushed to one side at one stage I think."
He added: "And the next minute we had to put a caption up and I was left talking to millions and millions of viewers trying to explain what was going on without necessarily being able to see all of it myself."
Later, Holmes said the protesters had been "well-orchestrated".
He said: "About six protesters ran out of the audience, very well positioned, very well orchestrated, they knew exactly the positions to be in and they tried to, well, I think, destroy the lottery machines.
"Fathers 4 Justice was the campaign and, you know, I think for the audience a very scary moment, whatever empathy or sympathy many people may have with Fathers 4 Justice, again, you've a lot of very shaken, disturbed people, both watching at home and in the studio."