Issue while parsing Multipart mime data

Hi All,
I am trying to parse multipart mime data in my service where I have input as a stream object.
The data seems to be coming correctly to the pipeline and when I convert it to string, I see exactly what was posted to the service from SOAP UI client, however when I pass the stream object to createMimeData inbuilt service, the mimeData output doesn’t contain the correct data and always return number of parts as 1.
Anyone aware on this issues?

Thanks & Regards,