Is there An Official Committee which regulates the English language, like the Académie française does for French?
No. There never has been any group or body with this authority and it is not the purpose of the Oxford English Dictionary Department to act in this way. There was considerable interest in the standardization of English in the 17th and 18th centuries which among other things resulted in the publication of Samuel Johnson's famous dictionary in 1755. However, despite the support of writers such as Daniel Defoe and Jonathan Swift, efforts to improve the language or to establish an English Academy were unsuccessful.
English is now used in so many countries and in so many contexts. That it is doubtful whether anyone would take much notice of an Academy even if one existed, though there are organizations dedicated to maintaining or improving standards of English usage such as the Plain English Campaign which tries to encourage the use of clear English rather than jargon especially in commercial, legal and official publications and the Queen's English Society which aims to counteract the perceived misuse and debasement of English.