A Ukip spokesman said that any breach of party rules would be investigated, but also criticised the exposure of candidate William Henwood's tweet by "the other parties."
A spokesman for the party told the BBC:
Any breach of our rules will be duly investigated and action will be taken.
However one has to question why the other parties are spending hours behaving like secret police and trawling through the social media of Ukip candidates who are everyday men and women, rather than actually doing politics.
Perhaps if they did they would be better able to tackle us on policy, rather than having to rely on smear campaigns to try to undermine Ukip's increasing popularity.
Were we to return the favour we would find an even greater wealth of embarrassment and disgrace in the other three parties' ranks to also spread across the media.
More top news
John Underhill said geological changes 55 million years ago mean the UK's geology is unsuitable for shale oil and gas production.
Argos will have to pay an additional £1.5 million to staff they underpaid, a government investigation has ruled.
The government reportedly plans to allow visa-free travel to continue after Brexit for visitors from the European Union.