The couple built up a lucrative business through producing fun bags and themed items for celebrations, such as the Queen’s Diamond Jubilee and their daughter's wedding.
But their Olympic themed party goods advertised under the heading "Celebrate the Games" have been investigated by the London Organising Committee of the Olympic Games.
Locog is keen to protect the integrity of official sponsorship deals with 55 companies worth £700 million.
The committee has apparently asked Party Pieces to change a page bearing a picture of the Olympic torch covered by a Union flag, reports the Daily Telegraph.
Another image to attract the attention of Locog was one of a woman throwing a javelin under the strapline: "Let the Games Begin".
Locog said in cases where firms breached rules enforcement officials would send them a warning letter or phone them. Only the most blatant breaches would result in further action.
"We will ring and explain the obligations and most times this dialogue is friendly.
"People are usually doing it to be part of the fun, but companies are not allowed to promote an association with the Games if they are not a sponsor.”