Tier 2 General Dependant Visa Application Status "Deferred"

Hi,

I have applied for Tier 2 General along with my wife and kid under tier 2 General Dependent.

We had done the Bio-metric on 5th Jan 2017.
I had enquired yesterday about the visa status and got information that
1. Main Applicant Visa - Decision made and document will be returned ASAP
2. Dependants - In Process
When I have enquired today –
1. Main Applicant Visa - Decision made and document will be returned ASAP
2. Dependants - Deferred saying more enquiries / investigation are in process.

Can somebody explain that Deferred status for dependent is due to normal delay or looks something wrong ?

It should be fine and they require some more time. Can you plesae tell me how do you enquiry about the status? By email or over phone?