NEW DELHI (Reuters) - India's Supreme Court has ordered the release of the founder-editor of a news portal accused by police of receiving illegal funding from China, saying his arrest was invalid more than seven months afterwards, his lawyers said on Wednesday.

Police arrested Prabir Purkayastha early in October and raided the New Delhi office of NewsClick and the homes of journalists and writers linked to the English-language news site.

On Wednesday, the court said Purkayastha was not notified of the grounds for his arrest in a timely manner, according to his lawyer, Arshdeep Singh Khurana.

Purkayastha will be released from custody after furnishing a bail bond to a lower court, said Nitin Saluja, another lawyer in the case.

The investigation began after a report in the New York Times in August identified NewsClick as part of a global network receiving funds from American billionaire Neville Roy Singham, allegedly to publish Chinese propaganda.

Police accused Purkayastha of conspiring to disrupt India's sovereignty and cause disaffection, saying he had received large funds from China to push biased news criticising Indian policies and projects and defending Chinese policies and programmes.

At the time, NewsClick said it does not publish news or information at the behest of any Chinese entity or authority, and does not take directions from Neville Roy Singham on its content.

Media rights watchdogs and opposition groups in India have called the investigation into NewsClick and the surrounding accusations part of a crackdown on the media - a charge dismissed by Prime Minister Narendra Modi's government.

(Reporting by Arpan Chaturvedi in New Delhi and Sudipto Ganguly in Mumbai; Editing by YP Rajesh and Clarence Fernandez)

By Arpan Chaturvedi and Sudipto Ganguly