Allan appeared after the committee's chairman, Damian Collins, took the unusual move of seizing a trove of confidential internal Facebook documents from a visiting USA tech executive.
The social media company has now asked the DCMS committee to refrain from reviewing those documents and to return them to counsel or to Facebook.
Damian Collins, chairman of the Commons Digital, Culture, Media and Sport (DCMS) Committee used a rare parliamentary mechanism and compelled Ted Kramer, the founder of Six4Three, a USA app software company, to hand over the documents who was on a business trip in London last week.
Mr Collins took direct aim at Facebook, stating that the company had "some very serious questions" to answer and had mislead the committee over Russian involvement in the platform. "In ignoring the inquiries of seven national parliaments, Mark Zuckerberg brought this escalation upon himself, as there was no other way to get this critical information", wrote Christopher Wylie, a whistleblower who was previously the director of research at Cambridge Analytica.
Collins said: "We are in uncharted territory".
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He sent the House of Commons serjeant-at-arms to seize documents from an American businessman involved in a legal dispute with Facebook.
"An unprecedented worldwide grand committee comprising 22 representatives from seven parliaments will meet in London next week to put questions to Facebook about the online fake news crisis and the social network's own string of data misuse scandals", TechCrunch reported on Friday.
"We have followed this court case in America and we believed these documents contained answers to some of the questions we have been seeking about the use of data, especially by external developers". They want to scrutinize Facebook over its handling of data privacy, most notably involving consultancy Cambridge Analytica's improper use of information from more than 87 million Facebook accounts to manipulate elections.
Allan pleaded with Collins not to raise the material at the hearing, which MPs are entitled to do under Parliamentary privilege, "until we have further guidance from the court".
Richard Allan, Facebook's vice-president for policy who is set to testify before Parliament after Zuckerberg declined to attend, stated that Facebook takes its responsibility around: "a number of important issues around privacy, safety and democracy ... very seriously".