Jack Toepfer took to Youtube to make other parents aware of this issue, in a video titled 'Throw out your bath toys!'.
The clip shows Jack holding a child's squeezable pirate bath toy and squeezing it into the bath.
To his shock, the toy squirted out black mould into the bathtub.
Wanting to warn parents of the potential dangers, he posted the video to Youtube and wrote: 'Any toys that hold water, that squirt water, or otherwise do not dry completely in an hour or so - throw them out.
'Your kids chew on these, drink out of them, and otherwise trust that they are clean because they are in a soapy bath, after all.
'All of this mould came out of this toy AFTER some had already squirted out in the bath, again onto a bath towel, and then what you see here.
'If I cut it open I'm sure I would find more. There is no way for these squeeze toys to dry completely so they sit, with water in them, in dark moist places - and it is mould paradise.
'If you have any now, throw them out. If your kids insist on using them, throw them out after the first bath. They are cheap and there are better bath toys out there.'
This isn't the first time this has been noticed, as last year, the popular children's teething toy Sophie the Giraffe came under fire for the same issue.
But there is still the question of how to clean toys like this, when there's no visible way to get inside them.
According to Livestrong.com, bath toys should be 'removed from the tub as soon as bath time is over'. All of the excess water should be dried off and the toys themselves should be shaken and squeezed to ensure no extra water is inside.
The best way to dry them fully is to pop them on a folded towel and open a window or turn on the air vent. They also suggest giving the toys a deep clean once a week.
'Soak the bath toys for up to 10 to 15 minutes’ in a bucket or basin of ‘hot water with white vinegar, aiming for a 2 to 1 ratio of hot water to vinegar.
'Squeeze the hot water and vinegar solution up into the toys and slosh it around before squeezing it all out. Rinse the toys well, and let them air dry in the sun', the advice reads.