While he says he was washing, sterilising and air-drying the bottle and cap each day, he couldn't get to the internal mechanisms of the lid, which he later noted are now unable to be fitted back together.
The post has been shared over 50,000 times and Beresford has since edited his original comment to note he never wanted to make a complaint, rather raise an issue and alert other parents to the problem.
"The post was started as a general warning to 'INSPECT' your bottle caps, not throw them away. It is not a witch-hunt, or an attempt to boycott the manufacturer. Hence the reason they were never informed, or tagged", he wrote.
He has since received numerous comments, some lamenting the same concerns over their child's drink bottle lids making them sick.
Despite not tagging Sistema in the post, the company has responded to parents concerns in a statement on their website.
"We take this feedback very seriously and have therefore posted on our website videos and instructions that demonstrate how to take apart and clean each of the three tops we currently have on the market.
"We manufacture our tops to meet international child safety standards and it is for this reason they can be difficult to disassemble."
Sistema's cleaning tips:
• Remove the cap from the bottle after use
• Extend the lid to open
• Put the top either in the dishwasher or hand wash and then place in water for five minutes with a sterilising solution.
- nzherald.co.nz