The Krassenstein brothers lost access to Twitter after they allegedly created and used multiple fake accounts to expand their reach.
"The Twitter Rules apply to everyone. Operating multiple fake accounts and purchasing account interactions are strictly prohibited. Engaging in these behaviours will result in permanent suspension from the service," news website Deadline reported quoted the micro-blogging site as saying on Friday.
However, in a post on Facebook, the brothers denied all claims against them.
"If Twitter wants to ban us for having multiple accounts then that's their right," wrote Ed Krassenstein.
"Our multiple accounts did not break any of Twitter terms, but it's their right to ban whoever they want. What they shouldn't be doing is smearing our names over and over again by claiming that we 'purchased account interactions'."
For now, the Twitter ban on the activist brothers seem permanent but it remains unclear if their strong denial could convince the micro-blogging site to lift the suspension on their accounts.
In 2016, the Krassensteins' Florida house was raided by federal agents suspecting their involvement in an international fraud ring. However, they claimed they had done nothing illegal and were not charged with any crime.
This is not the first instance where Twitter has been accused of banning prominent voices and earlier company CEO, Jack Dorsey, has also met with Trump to discuss his concerns, the report added.
( With inputs from IANS )