ABUJA (Reuters) - Nigeria’s Senate has withdrawn a report that largely exonerated South African mobile phone giant MTN of accusations of illegally repatriating $14 billion and that rebuked the Nigerian central bank for regulatory failures.

FILE PHOTO: An MTN starter kit pack on display at a retail stand in Abuja, Nigeria November 17, 2015. REUTERS/Afolabi Sotunde/File Photo

The report, presented to the Senate on Thursday and reviewed by Reuters, was almost immediately sent back for further work because it did not capture possible infractions by all stakeholders, two people familiar with the matter said.

The upper house of parliament agreed last September to investigate whether Africa’s biggest telecoms company unlawfully repatriated $13.92 billion from Nigeria - its most lucrative market which generates a third of its revenue - between 2006 and 2016.

MTN, which has denied any wrongdoing, could not immediately be reached for comment.

The crux of the allegation is that MTN did not obtain certificates declaring it had invested foreign currency in Nigeria within a 24-hour deadline stipulated in a 1995 law, and so the repatriation of returns on those investments was illegal.

The Senate formed a committee to investigate the allegations against MTN and financial institutions including the Central Bank of Nigeria (CBN) and commercial banks such as Nigeria’s Stanbic IBTC Bank PLC.

The committee’s report gave no recommendations for punitive measures against MTN.

Instead, the report rebuked Nigeria’s central bank for its failure to monitor fund transfers to and from the country, calling its oversight of banks “inadequate.”

The report recommended that the Senate “condemn the Central Bank of Nigeria for failing in its duty” to address problems with its monitoring of foreign exchange transfers.

The CBN’s duty is to correct and if needed sanction banks and their customers for any wrongdoing, which it never did, said the report, adding that the central bank never testified to the committee that there were any infractions.

By never applying sanctions, the CBN had lent credence to the banks’ argument that they were not breaking any rules by transferring foreign currency, the report said.

A CBN spokesman was not immediately available for comment.

However, the report also urged the central bank to “sanction Stanbic IBTC for improper documentations in respect of capital repatriation and loan repayments amounting to $388,195,183 and $199,440,952 respectively”.

Stanbic IBTC was not immediately available for comment.

The findings were met with dismay by some in the Senate.

Senators did not understand why the report largely condemned the CBN while MTN and named commercial banks which transferred money overseas were barely reprimanded, said one of the people familiar with the investigation.

The document is a “poorly investigated report full of indecent holes”, the person said, speaking on condition of anonymity.

The report has now been “withdrawn for consultations and further legislative work”, said the other person with knowledge of the investigation.

It is the latest regulatory issue affecting MTN in Nigeria. MTN paid 30 billion naira ($98 million) to the Nigerian government in part settlement of a 330 billion naira fine imposed on the telecoms group for not disconnecting unregistered SIM cards, an MTN source told Reuters in March.

($1 = 304.7000 naira)